SYNOPSIS

DESCRIPTION

This command provides a way to interact with p4 repositories
using Git.

Create a new Git repository from an existing p4 repository using
git p4 clone, giving it one or more p4 depot paths. Incorporate
new commits from p4 changes with git p4 sync. The sync command
is also used to include new branches from other p4 depot paths.
Submit Git changes back to p4 using git p4 submit. The command
git p4 rebase does a sync plus rebases the current branch onto
the updated p4 remote branch.

EXAMPLES

Clone a repository:

$ git p4 clone //depot/path/project

Do some work in the newly created Git repository:

$ cd project
$ vi foo.h
$ git commit -a -m "edited foo.h"

Update the Git repository with recent changes from p4, rebasing your
work on top:

$ git p4 rebase

Submit your commits back to p4:

$ git p4 submit

COMMANDS

Clone

Generally, git p4 clone is used to create a new Git directory
from an existing p4 repository:

$ git p4 clone //depot/path/project

This:

Creates an empty Git repository in a subdirectory called project.

Imports the full contents of the head revision from the given p4
depot path into a single commit in the Git branch refs/remotes/p4/master.

Creates a local branch, master from this remote and checks it out.

To reproduce the entire p4 history in Git, use the @all modifier on
the depot path:

$ git p4 clone //depot/path/project@all

Sync

As development continues in the p4 repository, those changes can
be included in the Git repository using:

$ git p4 sync

This command finds new changes in p4 and imports them as Git commits.

P4 repositories can be added to an existing Git repository using
git p4 sync too:

This imports the specified depot into
refs/remotes/p4/master in an existing Git repository. The
--branch option can be used to specify a different branch to
be used for the p4 content.

If a Git repository includes branches refs/remotes/origin/p4, these
will be fetched and consulted first during a git p4 sync. Since
importing directly from p4 is considerably slower than pulling changes
from a Git remote, this can be useful in a multi-developer environment.

If there are multiple branches, doing git p4 sync will automatically
use the "BRANCH DETECTION" algorithm to try to partition new changes
into the right branch. This can be overridden with the --branch
option to specify just a single branch to update.

Rebase

A common working pattern is to fetch the latest changes from the p4 depot
and merge them with local uncommitted changes. Often, the p4 repository
is the ultimate location for all code, thus a rebase workflow makes
sense. This command does git p4 sync followed by git rebase to move
local commits on top of updated p4 changes.

$ git p4 rebase

Submit

Submitting changes from a Git repository back to the p4 repository
requires a separate p4 client workspace. This should be specified
using the P4CLIENT environment variable or the Git configuration
variable git-p4.client. The p4 client must exist, but the client root
will be created and populated if it does not already exist.

To submit all changes that are in the current Git branch but not in
the p4/master branch, use:

$ git p4 submit

To specify a branch other than the current one, use:

$ git p4 submit topicbranch

To specify a single commit or a range of commits, use:

$ git p4 submit --commit <sha1>
$ git p4 submit --commit <sha1..sha1>

The upstream reference is generally refs/remotes/p4/master, but can
be overridden using the --origin= command-line option.

The p4 changes will be created as the user invoking git p4 submit. The
--preserve-user option will cause ownership to be modified
according to the author of the Git commit. This option requires admin
privileges in p4, which can be granted using p4 protect.

To shelve changes instead of submitting, use --shelve and --update-shelve:

OPTIONS

General options

Sync options

These options can be used in the initial clone as well as in
subsequent sync operations.

--branch <ref>

Import changes into <ref> instead of refs/remotes/p4/master.
If <ref> starts with refs/, it is used as is. Otherwise, if
it does not start with p4/, that prefix is added.

By default a <ref> not starting with refs/ is treated as the
name of a remote-tracking branch (under refs/remotes/). This
behavior can be modified using the --import-local option.

The default <ref> is "master".

This example imports a new remote "p4/proj2" into an existing
Git repository:

$ git init
$ git p4 sync --branch=refs/remotes/p4/proj2 //depot/proj2

--detect-branches

Use the branch detection algorithm to find new paths in p4. It is
documented below in "BRANCH DETECTION".

--changesfile <file>

Import exactly the p4 change numbers listed in file, one per
line. Normally, git p4 inspects the current p4 repository
state and detects the changes it should import.

--silent

Do not print any progress information.

--detect-labels

Query p4 for labels associated with the depot paths, and add
them as tags in Git. Limited usefulness as only imports labels
associated with new changelists. Deprecated.

--import-labels

Import labels from p4 into Git.

--import-local

By default, p4 branches are stored in refs/remotes/p4/,
where they will be treated as remote-tracking branches by
git-branch[1] and other commands. This option instead
puts p4 branches in refs/heads/p4/. Note that future
sync operations must specify --import-local as well so that
they can find the p4 branches in refs/heads.

--max-changes <n>

Import at most n changes, rather than the entire range of
changes included in the given revision specifier. A typical
usage would be use @all as the revision specifier, but then
to use --max-changes 1000 to import only the last 1000
revisions rather than the entire revision history.

--changes-block-size <n>

The internal block size to use when converting a revision
specifier such as @all into a list of specific change
numbers. Instead of using a single call to p4 changes to
find the full list of changes for the conversion, there are a
sequence of calls to p4 changes -m, each of which requests
one block of changes of the given size. The default block size
is 500, which should usually be suitable.

--keep-path

The mapping of file names from the p4 depot path to Git, by
default, involves removing the entire depot path. With this
option, the full p4 depot path is retained in Git. For example,
path //depot/main/foo/bar.c, when imported from
//depot/main/, becomes foo/bar.c. With --keep-path, the
Git path is instead depot/main/foo/bar.c.

--use-client-spec

Use a client spec to find the list of interesting files in p4.
See the "CLIENT SPEC" section below.

-/ <path>

Exclude selected depot paths when cloning or syncing.

Clone options

These options can be used in an initial clone, along with the sync
options described above.

--destination <directory>

Where to create the Git repository. If not provided, the last
component in the p4 depot path is used to create a new
directory.

Export tags from Git as p4 labels. Tags found in Git are applied
to the perforce working directory.

-n

--dry-run

Show just what commits would be submitted to p4; do not change
state in Git or p4.

--prepare-p4-only

Apply a commit to the p4 workspace, opening, adding and deleting
files in p4 as for a normal submit operation. Do not issue the
final "p4 submit", but instead print a message about how to
submit manually or revert. This option always stops after the
first (oldest) commit. Git tags are not exported to p4.

--shelve

Instead of submitting create a series of shelved changelists.
After creating each shelve, the relevant files are reverted/deleted.
If you have multiple commits pending multiple shelves will be created.

Conflicts can occur when applying a commit to p4. When this
happens, the default behavior ("ask") is to prompt whether to
skip this commit and continue, or quit. This option can be used
to bypass the prompt, causing conflicting commits to be automatically
skipped, or to quit trying to apply commits, without prompting.

--branch <branch>

After submitting, sync this named branch instead of the default
p4/master. See the "Sync options" section above for more
information.

--commit <sha1>|<sha1..sha1>

Submit only the specified commit or range of commits, instead of the full
list of changes that are in the current Git branch.

--disable-rebase

Disable the automatic rebase after all commits have been successfully
submitted. Can also be set with git-p4.disableRebase.

--disable-p4sync

Disable the automatic sync of p4/master from Perforce after commits have
been submitted. Implies --disable-rebase. Can also be set with
git-p4.disableP4Sync. Sync with origin/master still goes ahead if possible.

Hook for submit

The p4-pre-submit hook is executed if it exists and is executable.
The hook takes no parameters and nothing from standard input. Exiting with
non-zero status from this script prevents git-p4 submit from launching.

One usage scenario is to run unit tests in the hook.

Rebase options

These options can be used to modify git p4 rebase behavior.

--import-labels

Import p4 labels.

Unshelve options

--origin

Sets the git refspec against which the shelved P4 changelist is compared.
Defaults to p4/master.

DEPOT PATH SYNTAX

The p4 depot path argument to git p4 sync and git p4 clone can
be one or more space-separated p4 depot paths, with an optional
p4 revision specifier on the end:

"//depot/my/project"

Import one commit with all files in the #head change under that tree.

"//depot/my/project@all"

Import one commit for each change in the history of that depot path.

"//depot/my/project@1,6"

Import only changes 1 through 6.

"//depot/proj1@all //depot/proj2@all"

Import all changes from both named depot paths into a single
repository. Only files below these directories are included.
There is not a subdirectory in Git for each "proj1" and "proj2".
You must use the --destination option when specifying more
than one depot path. The revision specifier must be specified
identically on each depot path. If there are files in the
depot paths with the same name, the path with the most recently
updated version of the file is the one that appears in Git.

See p4 help revisions for the full syntax of p4 revision specifiers.

CLIENT SPEC

The p4 client specification is maintained with the p4 client command
and contains among other fields, a View that specifies how the depot
is mapped into the client repository. The clone and sync commands
can consult the client spec when given the --use-client-spec option or
when the useClientSpec variable is true. After git p4 clone, the
useClientSpec variable is automatically set in the repository
configuration file. This allows future git p4 submit commands to
work properly; the submit command looks only at the variable and does
not have a command-line option.

The full syntax for a p4 view is documented in p4 help views. git p4
knows only a subset of the view syntax. It understands multi-line
mappings, overlays with +, exclusions with - and double-quotes
around whitespace. Of the possible wildcards, git p4 only handles
…​, and only when it is at the end of the path. git p4 will complain
if it encounters an unhandled wildcard.

Bugs in the implementation of overlap mappings exist. If multiple depot
paths map through overlays to the same location in the repository,
git p4 can choose the wrong one. This is hard to solve without
dedicating a client spec just for git p4.

The name of the client can be given to git p4 in multiple ways. The
variable git-p4.client takes precedence if it exists. Otherwise,
normal p4 mechanisms of determining the client are used: environment
variable P4CLIENT, a file referenced by P4CONFIG, or the local host name.

BRANCH DETECTION

P4 does not have the same concept of a branch as Git. Instead,
p4 organizes its content as a directory tree, where by convention
different logical branches are in different locations in the tree.
The p4 branch command is used to maintain mappings between
different areas in the tree, and indicate related content. git p4
can use these mappings to determine branch relationships.

If you have a repository where all the branches of interest exist as
subdirectories of a single depot path, you can use --detect-branches
when cloning or syncing to have git p4 automatically find
subdirectories in p4, and to generate these as branches in Git.

For example, if the P4 repository structure is:

//depot/main/...
//depot/branch1/...

And "p4 branch -o branch1" shows a View line that looks like:

//depot/main/... //depot/branch1/...

Then this git p4 clone command:

git p4 clone --detect-branches //depot@all

produces a separate branch in refs/remotes/p4/ for //depot/main,
called master, and one for //depot/branch1 called depot/branch1.

However, it is not necessary to create branches in p4 to be able to use
them like branches. Because it is difficult to infer branch
relationships automatically, a Git configuration setting
git-p4.branchList can be used to explicitly identify branch
relationships. It is a list of "source:destination" pairs, like a
simple p4 branch specification, where the "source" and "destination" are
the path elements in the p4 repository. The example above relied on the
presence of the p4 branch. Without p4 branches, the same result will
occur with:

PERFORMANCE

The fast-import mechanism used by git p4 creates one pack file for
each invocation of git p4 sync. Normally, Git garbage compression
(git-gc[1]) automatically compresses these to fewer pack files,
but explicit invocation of git repack -adf may improve performance.

CONFIGURATION VARIABLES

The following config settings can be used to modify git p4 behavior.
They all are in the git-p4 section.

General variables

git-p4.user

User specified as an option to all p4 commands, with -u <user>.
The environment variable P4USER can be used instead.

git-p4.password

Password specified as an option to all p4 commands, with
-P <password>.
The environment variable P4PASS can be used instead.

git-p4.port

Port specified as an option to all p4 commands, with
-p <port>.
The environment variable P4PORT can be used instead.

git-p4.host

Host specified as an option to all p4 commands, with
-h <host>.
The environment variable P4HOST can be used instead.

git-p4.client

Client specified as an option to all p4 commands, with
-c <client>, including the client spec.

git-p4.retries

Specifies the number of times to retry a p4 command (notably,
p4 sync) if the network times out. The default value is 3.
Set the value to 0 to disable retries or if your p4 version
does not support retries (pre 2012.2).

Clone and sync variables

git-p4.syncFromOrigin

Because importing commits from other Git repositories is much faster
than importing them from p4, a mechanism exists to find p4 changes
first in Git remotes. If branches exist under refs/remote/origin/p4,
those will be fetched and used when syncing from p4. This
variable can be set to false to disable this behavior.

git-p4.branchUser

One phase in branch detection involves looking at p4 branches
to find new ones to import. By default, all branches are
inspected. This option limits the search to just those owned
by the single user named in the variable.

git-p4.branchList

List of branches to be imported when branch detection is
enabled. Each entry should be a pair of branch names separated
by a colon (:). This example declares that both branchA and
branchB were created from main:

List of p4 labels to ignore. This is built automatically as
unimportable labels are discovered.

git-p4.importLabels

Import p4 labels into git, as per --import-labels.

git-p4.labelImportRegexp

Only p4 labels matching this regular expression will be imported. The
default value is [a-zA-Z0-9_\-.]+$.

git-p4.useClientSpec

Specify that the p4 client spec should be used to identify p4
depot paths of interest. This is equivalent to specifying the
option --use-client-spec. See the "CLIENT SPEC" section above.
This variable is a boolean, not the name of a p4 client.

git-p4.pathEncoding

Perforce keeps the encoding of a path as given by the originating OS.
Git expects paths encoded as UTF-8. Use this config to tell git-p4
what encoding Perforce had used for the paths. This encoding is used
to transcode the paths to UTF-8. As an example, Perforce on Windows
often uses "cp1252" to encode path names.

git-p4.largeFileSystem

Specify the system that is used for large (binary) files. Please note
that large file systems do not support the git p4 submit command.
Only Git LFS is implemented right now (see https://git-lfs.github.com/
for more information). Download and install the Git LFS command line
extension to use this option and configure it like this:

git config git-p4.largeFileSystem GitLFS

git-p4.largeFileExtensions

All files matching a file extension in the list will be processed
by the large file system. Do not prefix the extensions with ..

git-p4.largeFileThreshold

All files with an uncompressed size exceeding the threshold will be
processed by the large file system. By default the threshold is
defined in bytes. Add the suffix k, m, or g to change the unit.

git-p4.largeFileCompressedThreshold

All files with a compressed size exceeding the threshold will be
processed by the large file system. This option might slow down
your clone/sync process. By default the threshold is defined in
bytes. Add the suffix k, m, or g to change the unit.

git-p4.largeFilePush

Boolean variable which defines if large files are automatically
pushed to a server.

git-p4.keepEmptyCommits

A changelist that contains only excluded files will be imported
as an empty commit if this boolean option is set to true.

git-p4.mapUser

Map a P4 user to a name and email address in Git. Use a string
with the following format to create a mapping:

On submit, re-author changes to reflect the Git author,
regardless of who invokes git p4 submit.

git-p4.allowMissingP4Users

When preserveUser is true, git p4 normally dies if it
cannot find an author in the p4 user map. This setting
submits the change regardless.

git-p4.skipSubmitEdit

The submit process invokes the editor before each p4 change
is submitted. If this setting is true, though, the editing
step is skipped.

git-p4.skipSubmitEditCheck

After editing the p4 change message, git p4 makes sure that
the description really was changed by looking at the file
modification time. This option disables that test.

git-p4.allowSubmit

By default, any branch can be used as the source for a git p4
submit operation. This configuration variable, if set, permits only
the named branches to be used as submit sources. Branch names
must be the short names (no "refs/heads/"), and should be
separated by commas (","), with no spaces.

git-p4.skipUserNameCheck

If the user running git p4 submit does not exist in the p4
user map, git p4 exits. This option can be used to force
submission regardless.

git-p4.attemptRCSCleanup

If enabled, git p4 submit will attempt to cleanup RCS keywords
($Header$, etc). These would otherwise cause merge conflicts and prevent
the submit going ahead. This option should be considered experimental at
present.

git-p4.exportLabels

Export Git tags to p4 labels, as per --export-labels.

git-p4.labelExportRegexp

Only p4 labels matching this regular expression will be exported. The
default value is [a-zA-Z0-9_\-.]+$.

git-p4.conflict

Specify submit behavior when a conflict with p4 is found, as per
--conflict. The default behavior is ask.

git-p4.disableRebase

Do not rebase the tree against p4/master following a submit.

git-p4.disableP4Sync

Do not sync p4/master with Perforce following a submit. Implies git-p4.disableRebase.

IMPLEMENTATION DETAILS

Changesets from p4 are imported using Git fast-import.

Cloning or syncing does not require a p4 client; file contents are
collected using p4 print.

Submitting requires a p4 client, which is not in the same location
as the Git repository. Patches are applied, one at a time, to
this p4 client and submitted from there.

Each commit imported by git p4 has a line at the end of the log
message indicating the p4 depot location and change number. This
line is used by later git p4 sync operations to know which p4
changes are new.